The invention resides in a method of controlling an internal combustion engine wherein a fuel injection begin is calculated on the basis of a momentary engine speed, and a correction value for the injection begin and a corrected fuel injection begin are determined for the control of the internal combustion engine.
In an internal combustion engine, the fuel injection begin, the injected fuel amount and the fuel injection end determine to a large extent the quality of the combustion and the composition of the exhaust gases. In order not to exceed the legal limits, these characteristic values are generally monitored and controlled by an electronic control unit. Particularly critical in this connection are the transitions from a stationary to a non-stationary operating state, for example, the addition of a load or the change from one constant speed value to a higher speed value.
DE 199 139 C1 discloses a method of controlling an internal combustion engine wherein the speed of the internal combustion engine is monitored in a speed-control circuit and, upon detection of a significant change in the load at the engine output, the injection begin is retarded. As a significant change in load for example the emersion of a ship propeller from the water, or, in a power generator, the disconnection of a load are mentioned.
DE 44 46 246 C2 discloses a method for the control of a load acceptance behavior and the acceleration behavior of an internal combustion engine with exhaust gas turbochargers. In this method, upon recognizing a load increase, the speed is controlled and, additionally, the fuel injection begin is advanced. The adjustment in this case is dependent on the cylinder pressure or a charge air pressure of an exhaust gas turbocharger. The method however is complicated to adjust and designed only for non-stationary operating conditions.
DE 199 08 726 C2 also discloses a method of controlling an internal combustion engine wherein an injection begin is calculated by way of a performance graph at least dependent on the actual engine speed. For improving the operating smoothness, additionally, a corrective injection begin is calculated. The control of the internal combustion engine occurs on the basis of a resulting injection begin which is formed from the injection begin and the injection begin correction. However, the method described therein is only conditionally usable in connection with a diesel engine.
It is the object of the present invention to provide a method of controlling an internal combustion engine, particularly a diesel engine which is easy to tune and takes the various operating conditions of the internal combustion engine appropriately into consideration.